In: Mechanical Engineering

Hot water from a boiler of power plant are discharged through a 0.2-m-diameter, thin-walled pipe with a velocity of 3.5 m/s. The pipe passes through a room whose air temperature is 3°C and the exterior surface of the pipe is uninsulated and pipe length is 30 m.

(a) At a position in the pipe where the mean water temperature is 40°C, determine the heat loss and the pipe wall temperature.

(b) If the pipe is covered with a 20-mm-thick layer of insulation (k = 0.5 W/m K) what are the pipe wall temperature, the outer surface temperature, and the heat loss?

Water flows upward and then is discharged to the right through a
3 inch diameter pipe elbow, at a steady flow rate of 1 cubic foot
per second, the gage pressure at the entrance to the elbow is 30
psi. What vertical and horizontal force is necessary to hold the
elbow stationary, neglecting any required torque.

In the boiler of a power plant are tubes through which water
flows as it is brought from 0.8 MPa, 150°C to 240°C at essentially
constant pressure. The total mass flow rate of the water is 100
kg/s. Combustion gases passing over the tubes cool from 1067 to 277
°C at essentially constant pressure. The combustion gases can be
modeled as air as an ideal gas. There is no significant heat
transfer from the boiler to its surroundings. Assuming steady...

Consider a 2.5cm diameter thin walled horizontal cylindrical
pipe that carries chilled water at about 5°C. The pipe is very long
and is indoors in a climate controlled area with essentially still
air. Design an insulation system that will reduce heat gain per
unit length of pipe by at least 75% as compared to the heat gain to
the bare pipe. Completely specify the insulation system (materials,
dimensions, etc.) you design.

6. Water steadily enters an extremely thin 100 m stainless steel
pipe with a diameter of 10 cm at a mass flow rate of 31.4 kg/s at
80 °C at 100 kPa. The convection heat transfer coefficient between
the ambient air (20 °C) and water pipe is ℎ = 120 ?/(?^2)?. You can
ignore the heat loss by radiation and assume the temperature of the
water and pipe surface are almost same but the temperature
Difference is very small but...

A thin-walled tube with a diameter of 6 mm and length of 20 m is
used to carry exhaust gas from a smoke stack to the laboratory in a
nearby building for analysis. The gas enters the tube at 200°C and
with a mass flow rate of 0.001 kg/s. Autumn winds at a temperature
of 15°C blow directly across the tube at a velocity of 7 m/s.
Assume the thermophysical properties of the exhaust gas are those
of air.
(a)...

A water pipe tapers down from an initial radius of R1
= 0.2 m to a final radius of R2 = 0.09 m. The water
flows at a velocity v1 = 0.86 m/s in the larger section
of pipe.
1. What is the volume flow rate of the water?
2. What is the velocity of the water in the smaller section?
3. Using this water supply, how long would it take to fill up a
swimming pool with a volume...

A water is flowing through a circular varying diameter pipe.
The water completely fills the pipe at all its sections.
1- What is the water velocity of the water at the first
section if you know that the diameter of the pipe at this section=
22 cm and the water is flowing at a rate of 2.5 m3/s?
2- What is the diameter of the pipe at the second section if
you know that the water velocity at this section...

Fully developed (both hydrodynamic and thermal) laminar flow is
pushed through a thin-walled circular pipe of diameter 13 mm. The
fluid flows through the pipe at a velocity of 0.1 m/sec, has a
density of 1000 kg/m^3, a dynamic viscosity of 855 x 10^-6 Pa-sec,
a specific heat of 4000 J/kg-K, a Prandtl number of 8, and a
thermal conductivity of 0.613 W/(m-K).
The outside of the pipe is subjected to uniform cross flow where
the free-stream velocity is 5...

Water flows through a cast iron pipe with a diameter of 30 mm.
The pipe is inclined at an angle of 3 degrees from horizontal and
is 40 m long. The water flows due to gravity only. What is the
maximum volume flow rate of the water?
You may ignore any minor loses.

The flowrate for water traveling through a horizontal 300 m-long
cast iron pipe with a diameter of 0.6 m and a pressure drop of 17.2
kPa is to be found. P.S. use iterative approach to find values of f
and then V using that f.

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